Method for using blood centrifugation device with movable optical reader

ABSTRACT

A centrifuge device that is used to centrifuge a fluid sample, such as a blood sample, to separate the fluid sample into its various component layers, and which is capable of measuring the length of the component layers to calculate cell counts for each layer. The centrifuge device includes a rotor assembly for rotating and thus centrifuging the fluid sample, and a movable optical reader device for reading the cell layers in the centrifuged sample. The centrifuge device is capable of accurately controlling the reading of the centrifuged sample based on the orientation of the rotor, so that the rotor can continue to rotate the centrifuged sample while the readings are being taken.

CROSS-REFERENCE TO RELATED APPLICATIONS

Related subject matter is disclosed and claimed in a copending U.S.patent application of Stephen C. Wardlaw entitled "Assembly for RapidMeasurement of Cell Layers", Ser. No. 08/814,536, filed on Mar. 10,1997; in a copending U.S. patent application of Stephen C. Wardlawentitled "Method for Rapid Measurement of Cell Layers", Ser. No.08/814,535, filed on Mar. 10, 1997; in a copending U.S. patentapplication of Michael R. Walters entitled "Centrifugally Actuated TubeRotator Mechanism" (Ser. No. 08/918,43); in copending U.S. patentapplications of Michael A. Kelly, Edward G. King, Bradley S. Thomas andMichael R. Walters entitled "Disposable Blood Tube Holder" and "Methodof Using Disposable Blood Tube Holder" Ser. Nos. 09/033,373 and09/033,199, filed on even date herewith; in copending U.S. patentapplications of Michael R. Walters entitled "Inertial Tube Indexer" and"Method for Using Inertial Tube Indexer" Ser. Nos. 09/032,931 and09/033,367, filed on even date herewith; and in copending U.S. patentapplication of Bradley S. Thomas, entitled "Flash Tube Reflector WithArc Guide" Ser. No. 09/032,935, filed on even date herewith, all of saidapplications being expressly incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates generally to a centrifuge device which iscapable of centrifuging a blood sample contained in a blood tube andalso reading the blood component layers formed in the blood tube as aresult of the centrifugation. More particularly, the present inventionrelates to a centrifuge device having a movable optical reader devicethat is capable of moving with respect to the blood tube to opticallyread the blood component layers in the entire centrifuged blood samplewhile the blood sample is being spun by the rotor of the centrifugedevice, and further having an indexing mechanism which rotates the bloodtube in the rotor about an axis substantially corresponding to thelongitudinal axis of the blood tube, while the rotor is spinning theblood tube, so that the component layers can be read by the opticalreader device from different locations about the circumference of theblood tube. The centrifuge device further has detectors for detectingthe centrifugation of the rotor to control the reading of the bloodtube, and the loading and unloading of the blood tube in the rotor.

As part of a routine physical or diagnostic examination of a patient, itis common for a physician to order a complete blood count for thepatient. The patient's blood sample may be collected in one of two ways.In the venous method, a syringe is used to collect a sample of thepatient's blood in a test tube containing an anticoagulation agent. Aportion of the sample is later transferred to a narrow glass sample tubesuch as a capillary tube. The open end of the sample tube is placed inthe blood sample in the test tube, and a quantity of blood enters thesample tube by capillary action. The sample tube has two fill lines atlocations about circumference, and the volume of blood collected shouldreach a level in the sample tube between the two fill lines. In thecapillary method, the syringe and test tube are not used, and thepatient's blood is introduced directly into the sample tube from a smallincision made in the skin. In either case, the sample tube is thenplaced in a centrifuge, such as the Model 424740 centrifuge manufacturedby Becton Dickinson and Company.

In the centrifuge, the sample tube containing the blood sample isrotated at a desired speed (typically 8,000 to 12,000 rpm) for severalminutes. The high speed centrifugation separates the components of theblood by density. Specifically, the blood sample is divided into a layerof red blood cells, a buffy coat region consisting of layers ofgranulocytes, mixed lymphocytes and monocytes, and platelets, and aplasma layer. The length of each layer can then be optically measured,either manually or automatically, to obtain a count for each bloodcomponent in the blood sample. This is possible because the innerdiameter of the sample tube and the packing density of each bloodcomponent is known, and hence the volume occupied by each layer and thenumber of cells contained within it can be calculated based on themeasured length of the layer. Exemplary measuring devices that can beused for this purpose include those described in U.S. Pat. Nos.4,156,570 and 4,558,947, both to Stephen C. Wardlaw, and the QBC®"AUTOREAD" centrifuged hematology system manufactured by BectonDickinson and Company.

Several techniques have been developed for increasing the accuracy withwhich the various layer thickness in the centrifuged blood sample can bedetermined. For example, because the buffy coat region is typicallysmall in comparison to the red blood cell and plasma regions, it isdesirable to expand the length of the buffy coat region so that moreaccurate measurements of the layers in that region can be made. Asdescribed in U.S. Pat. Nos. 4,027,660, 4,077,396, 4,082,085 and4,567,754, all to Stephen C. Wardlaw, and in U.S. Pat. No. 4,823,624 toRodolfo R. Rodriquez, this can be achieved by inserting aprecision-molded plastic float into the blood sample in the sample tubeprior to centrifugation. The float has approximately the same density asthe cells in the buffy coat region, and thus becomes suspended in thatregion after centrifugation. Since the outer diameter of the float isonly slightly less than the inner diameter of the sample tube (typicallyby about 80 μm), the length of the buffy coat region will expand to makeup for the significant reduction in the effective diameter of the tubethat the buffy coat region can occupy due to the presence of the float.By this method, an expansion of the length of the buffy coat region by afactor of about 4 and 20 can be obtained. The cell counts calculated forthe components of the buffy coat region will take into account theexpansion factor attributable to the float.

Another technique that is used to enhance the accuracy of the layerthickness measurements is the introduction of fluorescent dyes (in theform of dried coatings) into the sample tube. When the blood sample isadded to the sample tube, these dyes dissolve into the sample and causethe various blood cell layers to fluoresce at different opticalwavelengths when they are excited by a suitable light source. As aresult, the boundaries between the layers can be discerned more easilywhen the layer thickness are measured following centrifugation.

Typically, the centrifugation step and the layer thickness measurementstep are carried out at different times and in different devices. Thatis, the centrifugation operation is first carried out to completion in acentrifuge, and the sample tube is then removed from the centrifuge andplaced in a separate reading device so that the blood cell layerthickness can be measured. More recently, however, a technique has beendeveloped in which the layer thickness are calculated using a dynamic orpredictive method while centrifugation is taking place. This isadvantageous not only in reducing the total amount of time required fora complete blood count to be obtained, but also in allowing the entireprocedure to be carried out in a single device. Apparatus and methodsfor implementing this technique are disclosed in the aforementionedcopending applications of Stephen C. Wardlaw entitled "Assembly forRapid Measurement of Cell Layers", Ser. No. 08/814,536 which has issuedas U.S Pat. No. 5,889,581 and "Method for Rapid Measurement of CellLayers", Ser. No. 08/814,535 which has issued as U.S. Pat No. 5,888,184.

In order to allow the centrifugation and layer thickness steps to becarried out simultaneously, it is necessary to freeze the image of thesample tube as it is rotating at high speed on the centrifuge rotor.This can be accomplished by means of xenon flash lamp assembly thatproduces, via a lens and a bandpass filter, an intense excitation pulseof blue light energy (at approximately 470 nanometers) once perrevolution of the centrifuge rotor. The pulse of blue light excites thedyes in the expanded buffy coat area of the sample tube, causing thedyes to fluoresce with light of a known wave length. The emittedfluorescent light resulting from the excitation flash is focused by ahigh-resolution lens onto a linear CCD array. The CCD array is locatedbehind a bandpass filter which selects the specific wavelength ofemitted light to be imaged onto the CCD.

The xenon flash lamp assembly is one of two illumination sources thatare focused onto the sample tube while the centrifuged rotor is inmotion. The other source is an array of light-emitting diodes (LEDs)which transmits red light through the sample tube for detection by theCCD array through a second band pass filter. The purpose of thetransmitted light is to initially locate the beginning and end of theplastic float (which indicates the location of the expanded buffy coatarea), and the full lines. Further details of the optical readingapparatus may be found in the aforementioned copending applications ofMichael R. Walters entitled "Inertial Tube Indexer" Ser. No. 08/032931,and in the aforementioned copending application of Bradley S. Thomasentitled "Flash Tube Reflector with Arc Guide" Ser. No. 09/032925.

Since it is desirable to read the layers in the centrifuge blood samplewhile the centrifuged blood sample remains in the centrifuge, it is alsodesirable to insure that the readings are as accurate as possible. It istherefore necessary to accurately monitor the orientation of the rotorin which the blood sample is being centrifuged in relation to theoptical reading device, so that the optical reading device will performthe readings at the exact times that the centrifuged blood sample is inthe reading area. Since the rotor is spinning at several thousands ofrevolutions per minute, it is necessary to synchronize the readingperfectly with the rotation of the rotor so that the sample can be readwithout slowing down the rotation speed.

As described above, it is also desirable to rotate the sample tube aboutits longitudinal axis, so that readings can be taken at differentlocations about the circumference of the blood tube, thus providing amore accurate measurement of the lengths of the blood component layersin the centrifuged blood sample. Details of an indexing apparatus forperforming this function may be found in the aforementioned copendingapplication of Michael R. Walters entitled "Inertial Tube Indexer" Ser.No. 09/032,931. Additionally, it is also desirable to be capable ofreading different portions of the blood sample at different times.Furthermore, because the readings are based on light being transmittedthrough the centrifuged sample and light that is emitted from thecentrifuged sample in response to excitation light irradiated onto thecentrifuge sample, it is desirable to prevent light of unwantedwavelengths from being detected to improve the readings being taken bythe optical detector.

Accordingly, a continuing need exists for an apparatus which is capableof centrifuging a blood sample stored in a sample tube, and takingaccurate measurements of the component layers of the centrifuged bloodsample while the sample tube remains in the centrifuge device andcontinues to be rotated by the rotor of the centrifuge device.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a centrifuge devicethat is capable of centrifuging a blood sample contained in a sampletube, and accurately reading the component layers that are formed in theblood sample as a result of the centrifugation without removing thesample tube from the centrifuge device.

Another object of the invention is to provide a centrifuge device havinga component layer reader which is capable of scanning the centrifugedblood sample to read different portions of the centrifuge blood sampleat different times.

A further object of the invention is to provide a centrifuge devicewhich is capable of monitoring the orientation of the rotor in which theblood tube containing the blood sample being centrifuged is loaded, tocontrol the reading of the centrifuge blood sample and the loading andunloading of the blood sample tube.

Another object of the invention is to provide a movable optical reader,for use with the centrifuge device, which is capable of reading thecomponent layers in a centrifuge blood sample while the rotor of thecentrifuge device is continuing to rotate the centrifuged blood sample.

A still further object of the invention is to provide a movable opticalreader as described above, which includes an excitation light sourcethat irradiates light onto the centrifuge blood sample, and whichfurther includes a reading device which receives light emitted by thecentrifuge blood sample in response to the excitation light, to read thecomponent layers of the centrifuged blood sample, and which furtherincludes a filter array having a plurality of filters which areselectable to substantially prevent light having certain wavelengthsfrom being received by the reading device.

These and other objects of the invention are substantially achieved byproviding an optical reader assembly, adaptable for use in a centrifugedevice which operates to centrifuge a fluid sample, such as a bloodsample, comprising a carriage assembly which is adaptable to movablysupport an optical reader that is adaptable to receive light emittedfrom the blood sample. The optical reader assembly further includes adriving mechanism which is adaptable to move the optical reader in thecarriage assembly when the optical reader is being adapted to receivethe emitted light from the blood sample. The driving mechanism can movethe optical reader incrementally so that the optical reader can receivelight emitted from different portions of the blood sample at differenttimes. The optical reader assembly can further comprise an excitationlight source which is adaptable to emit excitation light toward theblood sample to cause the sample to emit the emitted light, and a filterarray having a plurality of filters which are selectable to preventlight having certain wavelengths from being received by the opticalreader when the optical reader is reading the blood sample. The opticalreader assembly also can include a transmission light source which isadaptable to emit transmission light towards the fluid sample, and theoptical reader can be further adaptable to receive a portion of thetransmission light passing through the blood sample.

The above objects of the invention, as well as other objects, arefurther substantially achieved by providing a centrifuge devicecomprising a rotor that is adaptable to rotate a container whichcontains a blood sample to separate the blood sample into a plurality ofcomponent layers in the container, and a detector device that isadaptable to detect the component layers in the container while therotor is rotating the container. The detector device can include thefeatures of the optical reader assembly discussed above. The centrifugedevice further can include a detector which detects the orientation ofthe rotor, to thus control the detector device to control the reading ofthe blood sample, as well as to position the rotor for loading andunloading of the blood sample container. The centrifuge device can alsoinclude detectors which detect whether the container has been loaded inthe rotor, and whether the container is properly secured in the rotor.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects of the invention will be more readilyappreciated from the following detailed description when read inconjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view of a centrifuge device in which theindexing apparatus according to the present invention can be used;

FIG. 2 is a detailed perspective view of the centrifuge device shown inFIG. 1, with the cover being removed to expose the internal componentsof the device;

FIG. 3 is a top plan view of the centrifuge device shown in FIG. 2;

FIG. 4 is a front plan view of the centrifuge device shown in FIG. 2;

FIG. 5 is a block diagram showing some of the electrical components ofthe centrifuge device shown in FIGS. 1 and 2;

FIG. 6 is a schematic illustrating an example of the relationshipbetween the rotor and optical reading device and some of theirassociated electrical and mechanical components of the centrifuge deviceshown in FIGS. 1-4;

FIG. 7 is a detailed exploded perspective view of the rotor assembly ofthe centrifuge device shown in FIGS. 1-4;

FIG. 8 is a bottom plan view of the rotor shown in FIG. 7;

FIGS. 9 is an exploded perspective view showing the relationship betweenthe rotor assembly, rotor motor optical carriage assembly, tube captureand release motor and associated engaging mechanism, and LED bar of thecentrifuge device shown in FIGS. 1 and 2;

FIG. 10 is an exploded perspective view of the optical carriage assemblyshown in FIG. 9;

FIG. 11 is an exploded perspective view of the optical circuitryassembly of the optical carriage assembly shown in FIG. 10;

FIG. 12 is a bottom plan view of an assembled optical circuitry assemblyshown in FIG. 11;

FIG. 13 is a front view of an assembled optical circuitry assembly shownin FIG.

FIG. 14 is a perspective view of the centrifuge device shown in FIG. 1,but with the rotor assembly oriented in the tube loading and unloadingposition;

FIG. 15A is a top plan view of the rotor assembly shown in FIG. 5, withthe top cover removed, in relation to the tube capture and releasemotor, and having the carrier tube holder assembly in the releasedposition;

FIG. 15B is a side view of the rotor assembly shown in FIG. 5 with itscover attached, in relation to the tube capture and release motor andthe engaging mechanism in the disengaged position;

FIG. 16A is a top plan view of the rotor assembly and as shown in FIG.10A, but with the tube holding assembly being positioned in theretracted position;

FIG. 16B is a side view of the rotor assembly, retractor assemblydriving motor and the retractor assembly as shown in FIG. 10B, but withthe retractor assembly driving motor engaging the retractor assembly;

FIG. 17 is a detailed assembled perspective view of the rotor as shownin FIG. 5, with a carrier tube about to be inserted into the carriertube accommodating recess;

FIG. 18 is a detailed assembled perspective view of the rotor as shownin FIG. 5, with the carrier tube inserted in the carrier tubeaccommodating recess;

FIG. 19 is a detailed perspective view of the carrier tube accommodatingrecess, indexing mechanism and tube holding assembly of the rotorassembly as shown in FIG. 5;

FIG. 20 is a detailed perspective view of the carrier tube accommodatingrecess and tube holding member of the rotor assembly as shown in FIG. 5,with a carrier tube being inserted in the carrier tube accommodatingrecess;

FIG. 21 is a detailed cross-sectional view of the rotor assembly havinga carrier tube inserted in the carrier tube accommodating recess astaken along lines 21--21 in FIG. 18;

FIG. 22 is a flowchart illustrating an example of steps performed by thecentrifuge device shown in FIG. 1 when performing centrifugation;

FIG. 23 is a flowchart illustrating an example of the steps performed bythe centrifuge device when performing the LED transmission readings;

FIG. 24 is a schematic illustrating the relationship between the flashtube, arc guide, CCD array, filters, LED bar and carrier tube when therotor assembly positions the carrier tube and the CPU energizes the LEDbar for reading the centrifuged blood sample by the LED transmission asdescribed with regard to FIG. 23;

FIG. 25 is a top view of the schematic shown in FIG. 22 illustrating therelationship of the CCD array and carrier tube when a first portion ofthe centrifuged sample in the carrier tube is being read;

FIG. 26 is a top view as in FIG. 25 with the CCD array being moved to aposition to read a second portion of the centrifuged sample in thecarrier tube;

FIG. 27 is a top view as shown in FIG. 25 with the CCD array beingfurther moved to another position to read a third portion of thecentrifuged sample in the carrier tube;

FIG. 28 is a flowchart showing an example of the steps performed by thecentrifuge device when performing open fluorescence readings;

FIGS. 29A-29C are schematics showing the relationships between the flashtube, arc guide, CCD array, filters, LED bar and carrier tube when therotor assembly positions the carrier tube and the CPU energizes theflash tube to perform open fluorescence readings, green emissionreadings or red emission readings;

FIG. 30 is a schematic showing the indexing of the carrier tube;

FIG. 31 is a flowchart showing an example of the steps performed by thecentrifuge device when performing green emission readings, red emissionreadings and indexing; and

FIG. 32 is a top view of the schematic shown in FIG. 29 showing therelationship between the CCD array and carrier tube when the CPU isperforming green emission readings and red emission readings.

Throughout the drawings, like reference numerals will be understood torefer to like parts and components.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A centrifuge device 100 according to an embodiment of the presentinvention is shown in FIGS. 1-4. FIG. 1 illustrates the centrifugedevice 100 having a cover 102 and a lid 104 which is positioned in anopen position. The centrifuge device 100 is a relatively compact devicehaving a weight of less than about 20 pounds, a width of less than about15 inches, a height of less than about 9 inches, and a depth of lessthan about 15 inches. However, the size and weight of the centrifugedevice 100 can be varied in accordance with desired designmodifications. The cover 102 and lid 104 can be made of a hard plasticor any other suitable material. As illustrated in FIGS. 2-4, the cover102 of the centrifuge device 100 has been cut away to expose theinternal components of the centrifuge device 100.

As shown in FIGS. 2-4, the block diagram of FIG. 5, and the schematic ofFIG. 6, the centrifuge device 100 includes a rotor assembly 106 that isdriven by a rotor motor 108 as controlled by a CPU 110 via a drive board111. The rotor assembly 108 is typically about 6.9 inches in diameter(but can have any practical diameter), and can be made of any suitablematerial such as a molded composite material, plastic, metal or thelike. The rotor motor 108 is a direct drive brushless DC motor and ismounted on vibration isolation mounts (not shown) to reduce acousticnoise and vibration effects on the optics.

The CPU 110 in this example is a 186 processor running at 40 Mhz. TheCPU 110 controls the rotor motor 108 via drive board 111 to rotatewithin a range of about 1,000 to 12,000 r.p.m. The CPU 110 can alsocontrol the rotor motor 108 to stop the rotor assembly 106 in a maximumof about 10 seconds. The CPU 110 also includes a "watchdog timer" whichis re-initialized every few seconds to keep the rotor motor 108 running.This "watchdog timer" feature creates a safety shutdown in the eventthat the CPU 110 fails.

The rotor motor assembly 106 is housed in the centrifuge device 100 suchthat the interior of the centrifuge device 100 is formed to contain therotor assembly 106 in an explosion containment chamber, which willcontain all fragments in case of rotor assembly failure at full rotationspeed. Neither the centrifuge device 100 as a whole, or any part fromit, can move outside of a 30 cm safety zone surrounding the centrifugedevice 100 as a result of rotor assembly failure.

As described in more detail below, the rotor assembly 106 includes acarrier tube accommodating recess 112 having an indexing mechanism 113located therein, the construction and operation of which can be found inthe aforementioned copending application of Michael R. Walters et al.entitled "Inertial Tube Indexer and Method for Using the Same" Ser. No.09/032,931, A carrier tube 114 as described in the aforementionedapplication of Edward G. King et al. entitled "Disposable Blood TubeHolder and Method for Using the Same" Ser. No. 09/033373 can be loadedinto the carrier tube accommodating recess 112 and engaged by theindexing mechanism 113 as described below. The rotor assembly 106further includes a calibration label 115 which is used to calibrate thecentrifuge device 100 as described in more detail below.

The centrifuge device 100 further includes a door release and lockmechanism 116, which includes a door lock 118 that is mechanicallyoperable, and also controllable by a door release/lock drive 119, suchas a motor or solenoid which is controlled by CPU 110 via the driveboard 111. As discussed in more detail below, the door release and lockmechanism 118 is operated by a user to release the door 104, and thusallow the door 104 to be positioned in the open position as shown inFIG. 1 to provide access to the rotor assembly 106 and, in particular,the carrier tube accommodating recess 112 for insertion and removal of acarrier tube 114. The door release/lock device 119 is also controlled bythe CPU 110 to control the door lock 118 to maintain the door 104 in theclosed and locked position when the rotor assembly 106 is being drivenby the rotor motor 108. A cover interlock sensor 120 senses when thedoor 104 is locked, and provides a signal to the CPU 110 to this effectvia the drive board 111.

As further shown, the centrifuge device 100 includes a tube capture andrelease motor 121 that is controlled by the CPU 110. As discussed inmore detail below, the CPU 110 controls the tube capture and releasemotor 122 to drive an engaging mechanism 122 to engage a tube holdingassembly of the rotor assembly 106 to allow a carrier tube 114 to beloaded into and removed from the carrier tube accommodating recess 112,and to release the tube holding assembly so that the tube holdingassembly secures the carrier tube 114 in the carrier tube accommodatingrecess 112. A rotor loaded sensor 123, which can be an optical sensor,detects when the engaging mechanism 122 has returned to its homeposition after engaging the tube holding assembly and provides a signalto CPU 110. The CPU 110 interprets this signal as an indication that acarrier tube 114 has been loaded into the rotor assembly 106.

As further illustrated, the centrifuge device 100 further includes anoptical carriage assembly 124 that includes a flash tube 126 that isenergized by a flash lamp circuit 127 as controlled by the CPU 110. Theoptical carriage assembly further includes a CCD array 128 which isdescribed in more detail below. The CCD array 128 is controlled by a CCDcontrol board 130 that is controlled by CPU 110 to operate incooperation with flash tube 126, so that when flash tube 126 is drivento emit light towards the carrier tube 114 loaded in the rotor 106, theCCD array 128 is controlled to read light that is illuminated by thecontents (e.g., a blood sample) of a capillary tube contained in thecarrier tube 114 in response to the light emitted by the flash tube 126.These and other features of the flash tube 126 and CCD array 128, aswell as the operation of the carriage assembly 124 as a whole, aredescribed in more detail below, and in the aforementioned copending U.S.patent application of Bradley S. Thomas entitled "Flash Tube ReflectorWith Arc Guide Ser. No. 09/032,935.

The optical carriage assembly 124 further includes an optics transportmotor 132 which controls the movement of the optical carriage assembly124 and, in particular, the movement of the CCD array 128, along guiderails 134 in a direction radial of the rotor assembly 106. The opticstransport motor 132 is controlled by CPU 110 to move the opticalcarriage array 124 in this manner so that the CCD array 128 can read theentire sample in the capillary tube contained in the carrier tube 114.

The centrifuge device 100 includes a rotor assembly orientation sensor135 which, as described in more detail below, senses when the rotorassembly 106 is oriented such that the carrier tube 114 is positionedbelow the CCD array 128, and provides a signal to CPU 110. When the CPU110 receives the signal from the rotor assembly orientation sensor 135,the CPU 110 determines the instant at which the flash tube 126 should beenergized. Specifically, the CPU 110 creates a digital delay between thetime it receives the signal from the rotor assembly orientation sensor135 and the time at which the flash tube 126 is energized. This delaytime varies to correct for variations in the speed of rotation of therotor assembly 106, and for mechanical tolerances. When the CPU 110determines that the flash tube 126 should be energized, the CPU 110controls the flash tube circuit 127 to drive the flash tube 126, andcontrols the CCD control board 130 to control the CCD array 128 to readthe light emitted from the sample in the capillary tube.

The optical carriage assembly 124 further includes a filter rack 136which includes a red emission filter 138, a green emission filter 139,and a blue blocking filter 140. The filter rack 136 is driven by filtermotor 137 to move in a direction indicated by Arrow A in FIG. 4, so thateach of the individual filters of the filter rack 136 can be positionedin front of the CCD array 128 as desired as described in more detailbelow. Each filter 138, 139, 141 in the filter rack 136 is capable offiltering out light having particular wavelengths from the light beingemitted by the sample in carrier tube 114, while allowing light of adesired wavelength to pass to the CCD array 128.

Additionally, the centrifuge device 100 includes an LED bar 141 which isdisposed below the motor assembly 106 and is controlled by CPU 110 viathe drive board 111 to emit light in the direction of rotor assembly106. This light can pass through slits 142 and 144 in the rotor assembly106, and be detected by CCD array 128 as the rotor assembly 106 rotates,to ascertain the presence and absence of a carrier tube 114 and thecorrect positioning of the carrier tube 114 in the carrier tubeaccommodating recess 112 as described in more detail below.

The centrifuge device 100 also includes an LCD graphics display 146 thatis controlled by the CPU 110 to display, for example, informationpertaining to the operation of the centrifuge device 100, andinformation pertaining to the readings of the sample in the capillarytube contained in the carrier tube 114 as taken by the centrifuge device100. The centrifuge device 100 further includes a thermal printer 148that uses a 2.25 inch to 2.75 inch wide tape and is controlled by theCPU 110 via a printer driver board 150 to print out informationpertaining to, for example, readings of the centrifuged sample in thecapillary tube as taken by the centrifuge device 100.

The centrifuge device 100 also includes a floppy disk drive 152, such asa 3.5 inch 1.44 Mb floppy drive, which can receive a standard floppydisk to which data, such as readings of the centrifuged sample, can bewritten by the CPU 110, or from which data, such as patient data,control information or the like can be read by the CPU 110.

Also, software updates can be provided to the CPU 110 by a floppy diskloaded into the floppy disk drive 152. Each time power is turned on forthe centrifuge device 100, the CPU 110 checks the floppy disk drive 152.If the floppy disk drive 152 contains a software distribution floppydisk on which is stored a newer version of the software, the newerversion of the software is automatically updated by the CPU 110 andhence, the software which controls the centrifuge device 100 isautomatically upgraded.

Additionally, the centrifuge device includes a power supply 154 whichcan, for instance, be plugged into an AC outlet to provide power to thecentrifuge device 100. The power supply 154 is designed for universaluse with an autoranging A.C. input allowing it to operate over acontinuous means voltage range of 90 VAC to 265 VAC and at 47 Hz to 63Hz. The guaranteed minimum starting voltage should be 80 VAC, and thepower supply 154 should be capable of brief periods of operation at upto 300 VAC. Steady state power consumption should not exceed 15.0 watts,and peak power during rotor assembly acceleration should not exceed 250watts. The centrifuge device 100 further includes a run/stop button 156which controls the centrifuge device 100 to begin centrifuging thesample, a fan 158 which can be controlled by the CPU 110 via the driveboard 111 to cool the internal components of the centrifuge device 100,and a plurality of interface ports 160 which are capable of coupling tothe CPU 110 various types of interface devices, such as a bar codereader, a PC type keyboard, a PC type printer, a RS-232 module, and soon. The centrifuge device 100 also includes a four button key pad 162which enables an operator to enter information to control the operationof the centrifuge device 100. The key pad 162 can be located, forexample, underneath a lid 164 which also provides access to the thermalprinter 148, so that printing paper can be replaced, ink cartridges canbe replaced, and so on.

The rotor assembly 106 will now be described in more detail with respectto FIG. 7. As shown in FIG. 7, the rotor assembly includes a rotor top170 and a rotor bottom 172 that are coupled together by screws 174 whichpass through corresponding openings 176 in the rotor top 170 and arereceived into corresponding screw receiving holes 178 in rotor bottom172. The rotor top 170 and rotor bottom 172 can be made of any suitablematerial, such as metal, plastic, or preferably, a molded, compositematerial. Also, the rotor top 170 and rotor bottom 172 can alternatelybe snap-fit together, bonded, fit together by any other suitablefastener.

The calibration label 116 attaches to the label section 180 of rotor top170. Also, rotor top 170 includes an opening 182 which, in cooperationwith the cavity arrangement 184 in rotor bottom 172, forms the carriertube accommodating recess 112.

The rotor assembly 106 further includes a carrier tube holder assembly186 that is biased by a compression spring 188 as is described in moredetail below. The carrier tube holder assembly 186 includes legs 190which pass through corresponding slotted openings 192 in the rotorbottom 172, and a projection 193 which is described in more detailbelow. The carrier tube holder assembly 186 further includes a cup 194which, as described in more detail below, receives an end of the carriertube 114 when the carrier tube 114 is received in the carrier tubeaccommodating recess 112 of the rotor assembly 106.

The rotor assembly 106 further includes an engaging pin 196 which ismounted in pin receiving recess 198 in the rotor bottom 172 so that thefront end of the pin 196 projects into the carrier tube accommodatingrecess 112 of the rotor assembly 106 and thus engages an end of thecarrier tube 114 that is inserted in the carrier tube accommodatingrecess 112 as will be described in more detail below. The rotor assemblyalso includes a light pipe 200 that is inserted into light pipereceiving opening 202 in the rotor bottom 172. As described in moredetail below, the light pipe 200 is configured so that light travelingin a direction radial to the rotor assembly 106 which enters the lightpipe 200 through a light pipe side opening 204 is redirected by thelight pipe 200 to exit the bottom of the rotor assembly 106 throughlight pipe bottom opening 206 in the rotor bottom 172.

The rotor assembly 106 further includes a pawl 208 that is secured tothe rotor bottom 172 by, for example, heat staking or in any othersuitable manner. The significance of pawl 208 is described in theaforementioned copending application of Michael R. Walters entitled"Inertial Tube Indexer" ser. No. 09/032,931.

The rotor assembly 106 also includes an index hub assembly 210 that iscoupled to a rotor hub assembly 212 by a screw 214 and limit pins 216.The index hub assembly 210 has a cut-out portion 213 to accommodate pawl208. A shaft portion 218 of the screw 214 passes through opening 220 inthe index hub assembly 210, and through a central opening 222 in therotor bottom 172, and a threaded portion 224 of the shaft portion 218screws into opening 226 in motor hub 212. The diameter of the head 226of the screw 214 is greater than the diameter of opening 218 in theindex hub assembly 210 and thus, the screw 214 secures the index hubassembly 218, rotor bottom 172 and motor hub 212 together. Since thediameter of central opening 222 in the rotor bottom 172 is greater thanthe diameter of shaft portion 218 of the screw 214, the index hub 210and motor hub 212 are rotatably coupled to the rotor bottom 172. Furtherdetails concerning the index hub 210, and the significance of thisrotatable connection can be found in the aforementioned copendingapplication of Michael R. Walters et al. entitled "Inertial TubeIndexer" Ser. No. 09/032,931.

As further illustrated, limit pins 216 are received and secured inrespective openings 230 in the motor hub 212, and also pass throughcorresponding arcuate slots 232 in the rotor bottom 172 and are receivedand secured in corresponding openings 234 in the index hub assembly 210.As shown in FIG. 8, which is a plan bottom view of the rotor bottom 172with the limit pins 216 and screw 214 shown in phantom, the arcuateslots 232 in the rotor bottom 172 limit the relative rotation of theindex hub assembly 210 and motor hub assembly 212 with respect to therotor bottom 172 to an angle θ. FIG. 8 also illustrates the slottedopenings 192 with the legs 190 of the carrier tube holder assembly 186shown in phantom, the light pipe bottom opening 206, the slit 144 (seeFIG. 2), and a slit 236 which substantially aligns with slit 142 in therotor top 170.

FIGS. 9 and 10 are exploded perspective views illustrating therelationship between, among other things, the optical carriage assembly124, rotor assembly 106, rotor motor 108, tube capture and release motor121 and the engaging mechanism 122, and the LED bar 141.

As illustrated, the rotor motor 108 is secured to a frame portion 238 ofthe centrifuge device 100, such that the drive shaft 240 of the rotormotor 108 passes through an opening 242 in the frame portion 238. Therotor motor 108 is secured to the frame portion 238 by fastening members244, such as screws, pins, rivets, or the like, which pass throughcorresponding openings 246 in the frame portion 238 and are receivedinto corresponding openings 248 in the rotor motor 108. The rotorassembly 106 is positioned over the top of the frame portion 238, andthe rotor hub assembly 212 (see FIG. 7) of the rotor assembly 106 iscoupled to the drive shaft 240 of the rotor by a clamp 250, screw 251and key 252 clamping arrangement, such that the rotor hub assembly 212rotates essentially in unison with the drive shaft 240 of the rotormotor 108. The frame portion 238 is secured into the centrifuge device100 by bolts 254 which are received into mounting holes (not shown) inanother frame portion 256 (see FIG. 4) of the centrifuge device 100.

As further illustrated, the LED bar 141 is mounted in an opening 258 ofthe frame portion 238, so that the LED bar 141 is positioned below therotor bottom 172 (see FIG. 7) of the rotor assembly 106. In thisexample, the LED bar 141 includes a row of sixteen 660 nm LED's, whichare bare die on ceramic substrate construction and arranged to emitlight in the direction toward the rotor bottom 172. The 16 LEDs arecovered by a TIR transmission lens having an integral 20°×80° lightshaping diffuser. The hybrid ceramic circuit board includes printedcurrent limiting resistors that are individually laser trimmed toproduce an intensity gradient from 100% at the rim of the rotor assembly106 to 40% toward the center of the rotor assembly 106. This compensatesfor the variation in exposure time due to an increase in linear velocitywith the radius of the rotor assembly 106.

As further illustrated, the rotor assembly orientation sensor 135includes an emitter assembly 260 which, in this example, includes alight emitting diode mounted to a printed circuit board, and a detectorassembly 262 which, in this example, includes a photodiode orphototransistor mounted to a printed circuit board. The printed circuitboard of the emitter assembly 260 includes openings 264. Fasteningmembers 266, which are screws (but can be any suitable type of fasteningmembers such as pins, rivets, or the like), pass through correspondingopenings 264 in the printed circuit board and are received intocorresponding openings 268 in the frame portion 238 to mount the emitterassembly 260 to the frame portion 238 as shown. Similarly, the printedcircuit board of detector assembly 262 includes openings 270 whichreceive corresponding fastening members 272 which, in this example, arescrews (but can be any suitable fastening members such as pins, rivets,or the like). The fastening members 272 are received into correspondingopenings 274 in the frame portion 238 to thus couple the detectorassembly 262 to the frame portion 238 as shown.

As further shown, the tube capture and release motor 121 includes aslotted opening 276 and an opening 278. A fastening member 280, such asa screw, is received into opening 278 and is further received into anopening (not shown) in the frame portion 238 to mount the tube captureand release motor 121 to the frame portion 238. A fastening member 282,such as a screw, is assembled with a washer 284 and passes throughslotted opening 276 in the tube capture and release motor 121, and isreceived into an opening 286 in the frame portion 238 to further securethe tube capture and release motor 121 to the frame portion 238. Beforethe fastening members 280 and 282 are fully tightened in theirrespective openings in the frame portion 238, the slotted opening 276enables the position of the tube capture and release motor 121 to beadjusted by allowing the tube capture and release motor 121 to be movedrelative to fastening member 282.

As further illustrated, the engaging mechanism 122 includes a gear 288,a shaft 290, bearings 292, and engaging member 294, a retainer ring 296and a flag 298. The gear 288 is coupled to the shaft 290 which passesthrough an opening in bearing 292 and into an opening 300 in the frameportion 238. After passing through opening 300, the shaft 290 passesthrough openings 302 and 304 of the engaging member 294, which has beenpositioned such that its legs 306 pass through respective openings 308in the frame portion 238. The shaft 290 then passes out of anotheropening (not shown) in frame portion 238 opposite to opening 300. Theend of the shaft 290 opposite to that at which gear 288 is attached isassembled to bearing 293, retainer ring 296 and flag 298. Hence, theretainer ring 296 retains the shaft 290 in the openings in the frameportion 238. The engaging member 294 is coupled to the shaft 290 so thatthe engaging member 294 rotates essentially in unison with the shaft290.

That is, as described in more detail below, the gear 288 engages with agear 310 that is driven by the tube capture and release motor 121, sothat as the gear 310 is rotated by the tube capture and release motor121, the gear 306 rotates the gear 288 and thus, rotates the shaft 290and engaging member 294. As illustrated, the legs 306 of engaging member294 pass through corresponding openings 308 in the frame portion 238 sothat the engaging portion 312 of the engaging member 294 is capable ofcontacting the legs 190 of the carrier tube holder assembly 186 is asdescribed in more detail below.

As further illustrated, a sensor bracket 314 is attached to the frameportion 238 by any suitable fastening member, such as screws, pins,rivets or the like. The rotor loaded sensor 123 is attached to thesensor bracket 314 and positioned in relation to flag 298 such that flagportion 318 of flag 298 is positioned in opening 320 of sensor 316 whenthe engaging member 294 is in the disengaged position as is described inmore detail below.

As further illustrated, the optical carriage assembly 124 includes anoptical circuitry assembly 322 that is mounted in an optical transportframe 324. Specifically, the optical transport frame 324 includes guiderail openings 326 into which guide rails 134 (see also FIG. 2) are held.One of the guide rails 134 also passes through a corresponding guiderail opening 328 in the optical circuitry assembly 322, to thus slidablysecure the optical circuitry assembly 322 to the optical transport frame324 as is described in more detail below. Set screws 330 pass throughcorresponding set screw openings 331 in the optical transport frame 324to secure the guide rails 134 in their respective guide rail openings326 in the optical transport frame 324.

As further illustrated, a home flag 332 is attached to the opticaltransport frame 324 by screws 333 as shown. The significance of the leafspring 332 is described below. A bolt 334 is assembled with a washer 336and passes through bolt opening 338 in the optical transport frame 324.A threaded portion 340 of the bolt 334 is received into threaded opening342 in the frame portion 238 to rotatably secure the optical transportframe and thus, rotatably secure the entire optical carriage assembly124 to the frame portion 238. The frame portion 238 has machinedsurfaces 344 and 346 which allow the optical transport frame 324 toslide with respect to the frame portion 238 when the optical carriageassembly 124 is rotated about bolt 334. Screws 348 are assembled withrespective washers 350, and the shaft portions of the screws are passedthrough slotted openings 352 in the optical transport frame 324 and arereceived into respective threaded openings 354 in the frame portion 238.An aligning screw 356 is threaded into a corresponding threaded opening358 in frame portion 238, and an alignment spring plunger 360 is fitinto a corresponding opening 362 in the frame portion 238.

During assembly of the optical carriage assembly 124 to the frameportion 238, the screws 348 are loosely screwed into the correspondingthreaded openings 354 in the frame portion 238. The aligning screw 356is then rotated further into opening 358 or further out of opening 358,as necessary, to rotate the optical carriage assembly 124 about bolt 334to thus position the CCD array 128 in alignment with the LED bar 140 andfor reading the centrifuged sample in the carrier tube in the rotorassembly 106 as is described in more detail below. That is, if thealigning screw 356 is screwed further into threaded opening 358, the endof the aligning screw 356 will abut against the optical transport frame324 and rotate the optical transport frame 324 (and hence the opticalcarriage assembly 124) in a counterclockwise direction about bolts 334when viewed from the top of the optical carriage assembly 124.Alternatively, if the aligning screw 356 is rotated further out ofthreaded opening 358, the force exerted on the optical transport frame324 by the alignment spring plunger 360 will cause the optical transportframe 324 (and thus the entire optical carriage assembly 124) to rotatein a clockwise direction about bolt 334 when viewed from the top of theoptical carriage assembly 124. Once the aligning screw 356 has beenadjusted to place the CCD array 128 in the desired alignment, the screws348 can be tightened into their respective openings 354 to secure theoptical transport frame 324 and the entire optical carriage assembly 124essentially immovably to the frame portion 238.

As further illustrated, the optical transport motor 132, which drives agear 364, is coupled to the optical transport frame 324 by screws 366and 368. Specifically, screw 366 passes through opening 370 in opticaltransport motor 132 and into corresponding opening 372 in the opticaltransport frame 324. Screw 368 is assembled to washer 374 and passesthrough slotted opening 376 in the optical transport motor 132, and isreceived into opening 378 in the optical transport frame 324. Theslotted opening 376 enables the position of the optical transport motor132 to be adjusted slightly before the screws 366 and 368 are fullytightened in their respective openings 372 and 378.

As shown in more detail in FIGS. 11-13, the optical circuitry assembly322 includes an optics frame 380 which includes the guide rail opening328 through which one of the guide rails 134 passes to slidably securethe optical circuitry assembly 322 to the optical transport frame 324.Bearings 382 are disposed inside the guide rail opening 328 at oppositeends of the guide rail opening 328. When the guide rail 134 passesthrough guide rail opening 328, the guide rail 134 also passes throughthe openings in bearings 382. The bearings 382 are made of nylon or anysimilar suitable material which reduces the friction between the portionof the surface of the optics frame 380 forming the guide rail openings328 and the outer surface of guide rail 134, to thus allow the opticsframe 380 to slide more freely along the guide rail 134.

A home flag 384 is mounted to optics frame 380 by fastening members 386,such as screws, rivets, pins or the like. A cam follower 385 isrotatably secured to the optics frame 380. The leaf spring 384 ispositioned so that it contacts the bottom of corresponding guide rail134, while cam follower contacts the top of that corresponding guiderail 134. Hence, the leaf spring 384 slides along the bottom of thecorresponding guide rail 134, and the cam follower 385 rotates along thetop of the guide rail 134, when the optical circuitry assembly 322 isbeing moved along the guide rails 134.

The optical circuitry assembly 322 further includes a CCD board assembly388 that is secured to the optics frame 380 by screws 390, which arereceived into openings 392 in the optics frame 380. The CCD array 128 ismounted to the CCD board assembly 388 such that when the CCD boardassembly 388 is mounted to the optics frame 380, the CCD array 128 isaligned with CCD opening 394 in the optics frame 380. A CCD shield 396fits into opening 394 to cover and thus protect the CCD array 128.

The CCD board assembly 388 further includes an optical sensor 398 havinga sensing opening 400. The optical sensor 398 and its sensor opening 400is positioned so that when the optics circuitry assembly 322 ispositioned in a "home" position along guide rails 134 as shown in FIG.9, the leaf spring 332 attached to optical transport frame 324 enterssensor opening 400 and thus is detected by optical sensor 398. The CCDboard assembly 388 further includes ribbon cables 402 through whichsignals are received from, for example, CPU 110 (see FIGS. 3 and 4), andthrough which signals are sent to, for example, CPU 110.

The optical circuit assembly 322 further includes a flash tube bracket404 that is mounted to the optics frame 380 by screws 406. The flashtube 126 is mounted into flash tube bracket 404 as described in moredetail in the aforementioned copending application of Bradley S. Thomasentitled "Flash Tube Reflector with Arc Guide" Ser. No. 09/032,935. Thecable 408 provides energizing power to the flash tube 126 as describedin more detail below.

The optical circuitry assembly 322 further includes screw plates 410that are mounted to the optics frame 380 by screws 412 which passthrough corresponding openings 414 in the screw plates 410 and arereceived into corresponding openings 416 in the optics frame 380. A lensmount 418 is mounted to the optics frame 380 by screws 420 which passthrough corresponding slots 422 in the screw plates 410, are assembledwith corresponding compression springs 424, and are received intocorresponding threaded openings 426 in the lens mount 418. A lens array428 which is described in more detail below, is mounted in lens recess430 in the lens mount 418 in a position where the lens array 428 issubstantially aligned with the CCD array 128. Leaf springs 432 aremounted to the optics frame 380 by screws 434, so that the leaf springs432 apply a force against lens mount 418 to help stabilize the lensmount 418 and thus help to restrain the lens array 428 from moving dueto vibration.

The optical circuitry assembly 322 further includes a rack 436 havingteeth 437 along its bottom the toothed plate 436 is secured to opticsframe 380 by screws 438 which pass through corresponding openings 439 inthe optics frame 380 and are received into corresponding openings 440 inthe toothed plate 436. The teeth 437 engage with the gear 364 that isdriven by optical transport motor 132 to move the optical circuitryassembly 322 in the direction indicated by arrow A in FIG. 9 and backagain reverse to that direction.

The optical circuitry assembly 322 further includes a filter rack 136which is described in more detail below and includes a green emissionfilter 138, a red emission filter 139 and a blue block filter 140. Thefilter rack 136 is slidably mounted to the optics frame 380 by guidebars 450 and 452. That is, guide bar 450 passes through opening 454 inthe filter rack 136 and is mounted to the optics frame 380. Guide bar452 passes through slot 456 in the filter rack 136 and is also mountedto the optics frame 380. Filter motor 138 is mounted to optics frame 380by screws 458 which pass through corresponding openings 460 in thefilter motor 138 and are received into corresponding openings 462 in theoptics frame 380. The filter motor 138 drives a drive pulley 464 whichis positioned in drive pulley opening 466 in the optics frame 380.Another drive pulley 468 is mounted to optics frame 380 by a screw 470.A filter drive cable 472 is coupled to a cable tension spring 474 andpasses around drive pulleys 464 and 468. The cable tension spring 474and the end of the filter drive cable 472 not connected to the cabletension spring 374 are connected to the filter rack 136. The filtermotor 138 is electrically connected to the CCD board assembly 388 asshown, so that the filter motor 138 is driven in accordance with signalsprovided from the CCD board assembly 338 which, for example, have beenprovided by the CPU 110. As described in more detail below, the filtermotor 138 rotates the drive pulley 464 to drive the filter drive cable472 about pulley 468, and thus convey the filter rack 136 along guidebars 450 and 452 to position different ones of the filters 138, 139 and140 in front of the lens array 428 for reasons discussed below. Thefilter frame bracket of the filter rack 136, to which the drive cableattaches, includes a home position flag 475 that is read by aninterrupter 476 under the CCD board assembly 338 to detect the homeposition of the filter rack 136.

The operations for loading a carrier tube 114 into the centrifuge device100 will now be described with regard to FIGS. 14-21, in particular.

When a carrier tube 114 is ready for loading into the centrifuge device100, an operator can enter a command via, for example, the key pad 162so that the microcontroller 110 will control the motor 108 to rotate therotor assembly 106 to the proper orientation for loading of the carriertube 114, as can be determined through the use of the rotor assemblyorientation sensor 135 as described below. This carrier tube loadingorientation is essentially 180° from the orientation, which is shown inFIG. 14, of the rotor assembly 106 as shown in FIGS. 1 and 2.

To detect the orientation of the rotor assembly 106, the emitter in theemitter assembly 260 of the rotor assembly orientation sensor 135 emitsa light signal toward the circumference of the rotor assembly 106. Whenthe light pipe 200 is at a position such that the light being emitted bythe rotor assembly orientation sensor 135 enters the light pipe 200through light pipe side opening 202 and is redirected through the lightpipe bottom opening 206, the light is detected by the detection in thedetector assembly 262 of the rotor assembly orientation sensor 135. Therotor assembly orientation sensor 135 then provides a signal to the CPU110, which interprets that signal as an indication that the rotorassembly 106 is oriented such that a carrier tube accommodating recess112 is below the CCD array 128 and thus, a carrier tube 114 in thecarrier tube accommodating recess 112 can be read by the CCD array 128.In using this detected orientation as a reference orientation, the CPU110 can continuously monitor and ascertain the orientation of the rotorassembly 106 at all times when the rotor assembly is being rotated.Therefore, the CPU 110 can determine when the rotor assembly 106 in thetube loading and unloading position as shown in FIG. 12.

FIG. 15A is a top plan view of the rotor assembly 106 as shown in FIG.5, with the rotor top 170 being removed to expose the interiorcomponents of the rotor assembly 106, such as the carrier tube holderassembly 186, spring 188, pin 196, light pipe 200, and the index hubassembly 210. FIG. 15A also illustrates the tube capture and releasemotor 121 and gear 310, the engaging mechanism 122, and rotor loadedsensor 123. FIG. 15B is a side plan view further illustrating therelationship between the tube capture and release motor 121, theengaging mechanism 122 which includes gear 288, shaft 290, engagingmember 294 and flag 298, rotor loaded sensor 123, the rotor assembly 106with its top 170 attached, and the rotor motor 108.

When the rotor assembly 106 has been oriented to the tube loadingorientation, the CPU 110 will control the tube capture and release motor121 to drive the engaging mechanism 122 to engage legs 190 of thecarrier tube holder assembly 186. Hence, as shown in FIGS. 16A and 16B,the engaging member 294 of the engaging mechanism 122 will pull thecarrier tube holder assembly 186 in the direction indicated by arrow Bin FIG. 16A against the force of spring 188. It is further noted that aslong as the rotor assembly 106 is oriented so that the engaging member294 engages at least one leg 190 of the carrier tube holder assembly186, the force exerted on that one leg 190 by the engaging member 294will be sufficient to rotate rotor assembly 106 as necessary to orientthe rotor assembly 106 so that the engaging member 294 will also engagethe other leg 190. When the carrier tube holder assembly 186 is in theposition indicated in FIG. 16A, a carrier tube 114 can be loaded intothe carrier tube accommodating recess 112 of the rotor assembly 106.

That is, the CPU 110 can operate the door release and lock mechanism 116(see FIG. 2) to release the door 104 of the centrifuge device 100 sothat the door 104 can be opened to provide access to the rotor assembly106. As shown in FIGS. 17 and 18, the carrier tube 114 can then beloaded into the carrier tube accommodating recess 112 in the rotorassembly 106 such that the front portion of the geared cap 476 of thecarrier tube 114 having gear teeth 275 is received into cup 194.

Once the carrier tube 114 has been loaded into the carrier tubeaccommodating recess 112, the door 104 of the centrifuge device 110 canthen be shut, and the centrifuge device 100 is ready to perform thecentrifugation on the sample in the capillary tube contained in thecarrier tube 114. The operator presses the start button 156 to instructthe CPU 110 to control the tube capture and release motor 121 to drivethe engaging member 294 of the engaging mechanism 122 back to theposition shown in FIG. 15B. When this occurs, the force applied by thespring 188 to the carrier tube holder assembly 186 moves the carriertube holder assembly 186 in the direction opposite to arrow B in FIG.16A. The pin 196 in the rotor assembly 106 then engages an opening 478at the bottom end of the carrier tube 114. Hence, the pin 196 and thecup 194 secure the carrier tube 114 in the carrier tube accommodatingrecess 112 at both ends of the carrier tube 114.

Placement of the carrier tube 114 in the carrier tube accommodatingrecess 112, and the relationship of indexing mechanism 113 and thegeared cap 476 of the carrier tube 114 can be further appreciated fromFIGS. 19 and 20. As shown in FIG. 19, the index hub assembly 210 isoriented such that the indexing mechanism 113 is positioned asindicated. As discussed above, index hub assembly 210 can rotate withrespect to the rotor bottom 172 in the direction indicated by arrow C aslimited by the limit pins 216. The cut-out portion 213 of the index hubassembly 210 is positioned as indicated to provide clearance for thepawl 208 when the index hub 210 rotates. As shown in FIG. 20, when thecarrier tube 114 is loaded into the carrier tube accommodating recess112 and rests in the cavity 184 in the rotor bottom 172, the front endof the geared cap 476 of the carrier tube 114 is received in cup 194 andthe pin 196 is received into the opening 478 at the opposite end of thecarrier tube 114. FIG. 21, which is a cut away view of the rotorassembly 106 having the carrier tube 114 mounted therein as shown inFIGS. 18 and 20, illustrates the relationship between the indexingmember 113, the pawl 208 and the geared cap 476 of the carrier tube 114more explicitly.

The operations pertaining to the centrifugation of the sample in thecapillary tube contained in carrier tube 114, as well as the reading ofthe centrifuged sample as performed by the centrifuge device 100, willnow be described with reference to FIGS. 22-32 in particular.

After the carrier tube 114 which holds the capillary tube containing thesample (e.g., uncoagulated blood) is loaded into the rotor assembly 106in the manner described above, starting in step 1000 in the flowchartshown in FIG. 22, the centrifuge device 100 can begin the centrifugingprocess to centrifuge the sample to separate the components of thesample into individual layers. It is noted that when the centrifugedevice 100 has initially been activated, it can spin the rotor 106 toperform a calibration of the optics using the calibration decal 115.Initially, after the door 104 has been closed, the CPU 110 can controlthe drive board 111 to drive the LED bar 141 (see FIGS. 3 and 4) to emitlight toward to bottom of the rotor assembly 106 in step 1010. If theCCD array 128 detects light through the slit 142 in the top of the rotorassembly 106 when the corresponding slit 236 in the rotor bottom 172 isabove the LED bar 141 when the rotor assembly 106 is at the tube loadingand unloading orientation as shown in FIG. 14, the CPU 110 couldinterpret this detection as an indication that the carrier tube holderassembly 186 has not properly engaged the carrier tube 114.

That is, as can be appreciated from FIGS. 15A and 16A, when the carriertube 114 has been loaded properly in the carrier tube accommodatingrecess 112 and is engaged properly with the tube holder assembly 186,the projection 193 will obstruct the opening 236, so that essentially nolight emitted by the LED bar 140 will be allowed to pass through slit142 in the rotor top 170 when corresponding slit 236 in the rotor bottom172 is over LED bar 141. However, if the carrier tube 114 is not heldproperly by the carrier tube holder assembly 186, or the geared cap 476is not properly capped onto the carrier tube projection 193 of the tubeholder assembly 186 will not completely obstruct slit 236. In thisevent, light will pass through slit 236 at the edge of the slit 236closest to the carrier tube 114 if the cap 476 is not on the tube farenough, and at the edge of the slit 236 furthest from the carrier tube114 if the cap 476 is too far on the tube (e.g., if the glass capillarytube is fractured). The light will then pass through corresponding slit142, and thus be detected by CCD array 128. The CPU 110 will interpretthis detection as indicating improper carrier tube loading, and thus,will take corrective action, such as proceeding to step 1020 to displayan error message on the LCD display 146 and prevent rotation of therotor assembly 106.

Presuming that the CCD array 128 has not detected any light from the LEDbar 140 passing through slit 142, the CPU 110 can interpret thisnon-detection of light as an indication that the carrier tube 112 hasbeen loaded properly in the rotor assembly 106. The CPU 110 can thencontrol the rotor motor 108 in step 1030 to begin rotating the rotorassembly 106, and can control the CCD array 128 (see FIGS. 2-4) todetect for the presence of the light emitted by the LED bar 141 at theappropriate respective times when the slits 144 and 236 are directlyover the LED bar 141. That is, during the initial rotation period whichlasts for about 1 minute, the CPU 110 controls the rotor motor to rotatethe rotor assembly 106 at a relatively slow speed (e.g., 1000 r.p.m.).This slow rotation gently forces the blood in the capillary tubecontained in the carrier tube 114 into contact with the dried reagentsin the sample tube, which is described in more detail in theaforementioned copending U.S. patent application to King et al. entitled"Disposable Blood Tube Holder" Ser. No. 09/033373. This slow rotationalso causes the float in the sample tube to descend from the top of thetube toward the plugged end of the tube. The CPU 110 can control the LEDbar 140 to emit light towards the bottom of the rotor assembly 106 at,for instance, the corresponding times that the slits 144 and 236 aredirectly over the LED bar 140. If the CCD array 128 detects light fromthe LED bar 141 when the opening 144 is over the LED bar 141, the CPU110 will interpret this light detection as an indication that a carriertube 114 is not present in the carrier tube accommodating recess 112.If, for example, the CPU 110 detects that the carrier tube 114 is nolonger present in the carrier tube accommodating recess 112 while therotor assembly 106 is being rotated, the CPU 110 can interpret this asan indication that the carrier tube 114 has become dislodged from thecup 194 and pin 196, and has possibly been ejected from the rotorassembly 106. In this event, the CPU 110 can, for example, control theLCD display 146 to display an error message, and control the rotor motor108 to discontinue rotation of the rotor assembly 106.

On the other hand, if the CCD array 128 detects light through slit 142in the top of the rotor assembly when the corresponding slit 236 in thebottom of the rotor assembly 106 is above the LED bar 140, the CPU 110could interpret this detection as an indication that the carrier tube114 is no longer properly being held by the carrier tube holder assembly186. The CPU 110 could then take corrective action, such as displayingan error message on the LED display 146 and stopping rotation of therotor assembly 106.

Presuming that none of these problems have occurred, and therefore, thecarrier tube 114 remains properly loaded in the carrier tubeaccommodating recess 112, the CPU 110 will begin to perform the highspeed centrifugation process in step 1040. That is, the CPU 110 willcontrol the rotor motor 108 to accelerate rotation of the rotor assembly106 until the rotor motor 108 rotates the rotor assembly at a speed ofapproximately 11,000 r.p.m. This acceleration to 11,000 r.p.m. takesapproximately 10 seconds to occur. The rotor motor 108 will rotate therotor assembly 106 at this nominal speed of approximately 11,000 r.p.m.for approximately 3 minutes (e.g., 170 seconds). This high speedrotation creates a force of approximately 14,000 g at the rim of therotation assembly 106 to separate and pack the cells in the blood samplein the sample tube contained in the carrier tube 114 into 5 distinctpacked cell bands. The rotational speed of the rotor assembly 106, aswell as the high speed centrifugation time, naturally can be changed asdesired. Also, during the high speed centrifugation, the CPU 110 cancontinue to control the LED bar 140 and CCD array 128 in the mannerdescribed above to detect whether the carrier tube 114 has becomeimproperly held in the rotor assembly 106 or dislodged from the rotorassembly 106.

The CPU 110 then proceeds to step 1050 where the rotation of the rotorassembly 106 down to approximately 2,400 r.p.m. This deceleration toapproximately 2,400 r.p.m. takes about 10 seconds. The CPU 110 will thenproceed to step 1060 to begin performing the steps for reading thecentrifuged blood sample in the sample tube contained in the carriertube 114 as described with regard to the flowchart in FIG. 23.

The relationship between the CCD array 128, flash tube 126, arc guide405, blue excitation filter 407, lens array 428, filters 138, 139 and140, LED bar 141, and the carrier tube 114 is shown in a schematic inFIG. 24. This figure also illustrates the sample tube 478 which containsthe blood sample and which is in the carrier tube 114.

In step 1070, the CPU 110 controls the filter motor 137 to drive thefilter rack 136 along guide bars 450 and 452 as discussed above withregard to, for example, FIG. 11, until the blue block filter 140 ispositioned in front of the CCD array 128 as shown in FIG. 24. At thistime, the CPU 110 in step 1080 also controls the optical transport motor132 to move the optical circuitry assembly 322 to the far end of theguide rails 134 so that the CCD array 128 is positioned as shown in FIG.25 to read the portion of the sample at the end of the sample tube 478closest to the cap 476 (not shown). This figure also illustrates thefill lines 480 present on the sample tube, and the float 482 in thesample tube 478. It is noted that the optical sensor 398 (FIG. 11) onthe optical circuitry assembly 322 detects the leaf spring 332 on theoptical transport frame 324 when the optical circuitry assembly 322 isin this position, and provides an appropriate signal to the CPU 110 sothe CPU 110 can stop movement of the optical circuitry assembly 322.

When the CPU 110 determines from the signals provided by the rotorassembly orientation sensor 135 that the rotor assembly is oriented suchthat the carrier tube 114 is in a position to be read (i.e., in aposition essentially directly below the CCD array 128), the CPU 110 willenergize the LED bar 141 in step 1190 to emit light toward the rotorbottom 172. That light passes through slit 144 in the rotor bottom (see,for example, FIGS. 2 and 3) and impinges on carrier tube 114. A portionof the light emitted by LED bar 141 will be absorbed by the centrifugedsample, float, and plug in the blood tube contained in the carrier tube114. The light that is not absorbed passes through carrier tube 114,through lens array 428 and enters the blue block filter 140. The blueblock filter prevents essentially all light having a wavelength lessthan 530 nm from passing through the filter 140 and being received bythe CCD array 128. Primarily, the blue block filter 140 functions toprevent blue light of the stroke excitation source (i.e., flash tube 126and blue excitation filter 407) from entering the CCD array 128.

As shown in FIG. 24, when the above reading has been taken, it is notedthat the length of the CCD array 128 will enable it to receive the lightfrom only about 1/3 of the length of the centrifuged sample in thesample tube contained in the carrier tube 114. Therefore, in step 1100,the CPU 110 will determine if all of the desired reading has beencompleted. If not, the CPU 110 will control the optical transport motor132 to step 1110 to move the optical circuitry assembly 322 (and thusthe CCD array 128) along guide rails 134 in the direction indicated byarrow A in FIGS. 3, 9 and 24, until the CCD array 128 is positioned asshown in FIG. 26.

The CPU 110 then returns to step 1090 as described above. The CPU 110will determine when the carrier tube 114 is in a position for reading,and in step 1090 energize the LED bar 141, and control the CCD array 128to detect the unabsorbed portion of the light. The CPU 110 will thendetermine in step 1100 whether the reading is complete. If not, the CPU110 will proceed to step 1110 where it will control the opticaltransport motor 132 to move the CCD array 128 further in the directionindicated by arrow A in FIGS. 3, 9 and 26 so that the CCD array 128 ispositioned as shown in FIG. 27. The CPU will then return to step 1190,where it will control the LED bar 141 to emit light as described above,and control the CCD array 128 to detect the light passing through thesample in the carrier tube 114.

The CPU 110 will then determine in step 1100 that the initial readingprocess has been completed, and proceed to calculate results based onthese initial reads in step 1120. Specifically,these initial LEDtransmission readings are performed to locate the two fill lines 480 onthe blood tube 478 which contains the centrifuged blood sample to verifythe size of the blood tube 478. That is, with conventional blood tubes,the location of the fill lines is an indicator to the type of the bloodtube. The fill lines 480 will block the light emitted from the LED bar141 from passing through the blood tube 478, and thus, the CCD array 128will be able to detect the absence of the light in proportion to thewidth and position of the fill lines. If the CPU 110 determines based onthe detected readings of the fill lines that an improper type of bloodtube is being used, the CPU 110 can cause the graphics display 146 todisplay an error message, for example. Also, by determining the type ofthe blood tube based on the width of the fill lines, the CPU 110 willdetermine the appropriate formula needed to calculate the cell counts inthe layers for that size tube.

The LED transmission readings also detect the position of the float 482as it is suspended in the blood tube. The details of the float and bloodtube can be found in the aforementioned related U.S. patent applicationto Kelly et al. entitled "Disposable Blood Tube Holder" Ser. No.09/033370. Since the float 482 occupies some volume in the blood tube,the level of centrifuged blood in the blood tube will have risen abovethe fill lines 480. Nevertheless, because the volume of the float 482 isknown, the CPU 110 will be able to determine based on the position ofthe meniscus 484 in relation to the fill lines (as is detected asdescribed below) whether the blood tube has been filled with the properamount of blood. This entire process for performing these initialtransmission readings can take approximately 5 seconds.

The CPU 110 will then proceed to the sample reading process beginning atstep 1130 as shown in the flow chart of FIG. 28. The CPU 110 willinitially perform an open fluorescence reading process beginning at step1130. In doing so, the CPU will select the appropriate filter to bepositioned in front of the CCD array 128. As shown in FIGS. 29A-29C, theCPU 110 can control the filter motor 137 to position the blue blockfilter 140 in front of the CCD array 128 (FIG. 29A), to position thegreen emission filter 138 in front of the CCD array 128 (FIG. 29B), andto position the red emission filter 139 in front of the CCD array 128(FIG. 29C). In this example, the CPU 110 causes the filter motor 137 tokeep the blue block filter 140 in front of the CCD array 128, as shownin FIG. 29A. In step 1140, CCD array 128 is returned to the position inrelation to the carrier tube 114 as shown in FIG. 25.

When the CPU 110 determines based on the signals provided by rotorassembly orientation sensor 135 that the rotor assembly 106 is orientedso that the carrier tube 114 is in position so that the centrifugesample in the blood tube can be read, the CPU 110 in step 1150 controlsthe flash tube 126 to emit light. As shown in FIG. 29A, the lightemitted by the flash tube passes through blue excitation filter 407 andimpinges on the carrier tube 114. This emitted light causes certaincomponents in the centrifuged blood sample to fluoresce. Namely, theblood plasma, and components in the buffy coat region fluoresce inresponse to this light. Additionally, the plug 486 in the bottom of theblood tube also fluoresces. Furthermore, at that time, the CPU 110 alsocontrols the CCD array 128 to receive the light being emitted from thecomponents in the blood tube. The CPU 110 receives the signals from theCCD array 128 indicative of the detection, and stores those signals.

In step 1160, the CPU 110 determines if the desired amount of readingshave been taken with the CCD 128 array in that position and the carriertube 114 at that orientation. If the CPU 110 determines that furtherreading is to be taken, the CPU 110 will proceed to step 1170 todetermine if the carrier tube 114 should be indexed. If indexing is tooccur, the CPU 110 proceeds to step 1180 where it performs an indexingoperation as described in more detail in the aforementioned copendingpatent application to Michael R. Walters et al. entitled "Inertial TubeIndexer" Ser. No. 09/032,931. Specifically, the CPU controls the rotormotor 108 to cause the indexing mechanism 113 to index or rotate thecarrier tube 114 in a direction indicated by arrow INDEX as shown inFIG. 30. Once this indexing process has occurred, the CPU returns tostep 1150, where it controls the flash tube 126 to emit light and theCCD array 128 to receive the fluorescent light that is generated by thecomponents in the sample tube 478 and described above.

The CPU then repeats steps 1160-1180 as described above until itdetermines in step 1170 that no further indexing is to occur. When theCPU 110 determines that no further indexing of the carrier tube 114 isto occur when the CCD array 128 is at this current position, the CPUproceeds to step 1190 where it determines whether all of the reading hasbeen completed. If all of the reading has not yet been completed, theCPU proceeds to step 1200 where it moves the CCD array 128 to anotherposition as shown, for example, in FIGS. 26 and 27. The CPU then returnsto step 1150 to control the flash tube 126 and CCD array 128 to take areading of the centrifuged sample at this new position. The processingcontinues through steps 1160 through 1190 to perform the desiredindexing and reading as described above. If the CPU determines in step1190 that all of the desired reading at all of the positions along thecarrier tube 114 have been taken, the CPU will proceed to step 1210where it will process the results of the readings to calculate, forexample, the position of the meniscus 44 of the centrifuge sample andthe plug 486 in the sample tube 478. The CPU 110 then proceeds to step1210 to process the results as described above, and proceeds to step1220 to perform the further reading steps described in the flow chartshown in FIG. 31.

In particular, in step 1230 the CPU 110 will control the filter motor137 to move the filter rack 136 to position the green emission filter138 in front of the CCD array as shown in FIG. 29B. This green emissionfilter will allow light having a wavelength between about 520-560 nm topass to the CCD array 128. The CPU 110 in step 1240 controls the opticaltransport motor 132 to move the optical circuit assembly 322, and thus,the CCD array 128 to the appropriate position which will enable the CCDarray 128 to detect light being emitted by the buffy coat region in thecentrifuge blood sample. As described above in the background section ofthis application, the float in the blood tube will expand the buffy coatregion in the blood tube. Therefore, the CPU 110 will position the CCDarray 128 so that it receives light emitted from the sample in the areaat which the float 482 is suspended in the sample. As discussed above,the location of the float 482 in the sample has been determined by theLED transmission readings and open fluorescence readings. This positionis shown in FIG. 32.

When the CPU 110 determines from the signals provided by the rotorassembly orientation sensor 135 that the rotor assembly 106 is orientedso that the carrier tube 114 is in a position for reading, the CPU 110in step 1250 will control the flash tube 126 to emit light. The emittedlight passes through blue excitation filter 407 and impinges onto thecarrier tube 114. As discussed above, this light causes the componentsin the centrifuge blood sample to fluoresce. In particular, theplatelets and granulocytes in the buffy coat region will emit an orangecolor light, and the lymphocytes and monocytes in the buffy coat regionwill emit a green color light. The CPU 110 at that time will alsocontrol the CCD array 128 to receive the emitted light. The greenemission filter 138 allows the green color light being emitted from thelymphocytes and monocytes to be received by the CCD array 128, whileblocking light of other wavelengths such as the orange color lightemitted by the platelets and granulocytes. The signals detected by theCCD array 128 are provided to the CPU 110 and stored.

The CPU then proceeds to step 1260 to determine if all the readings forthat particular filter at that particular orientation of the carriertube 114 has been performed. If not, the CPU returns to step 1250 andcontrols the flash tube 126 and CCD array 128 to obtain another reading.

Once the CPU determines in step 1260 that all the reading with thatfilter (i.e., the green emission filter 138) has been performed at thatorientation of the carrier tube 114, the CPU proceeds to step 1270 whereit determines whether all of the reading has been completed. Since thisis the first reading that has been taken with the green emission filter138 in position in front of the CCD array 128, the CPU 110 willdetermine that further reading with the red emission filter 139 must beperformed. Hence, the CPU will proceed to step 1280 where it willcontrol the filter motor 137 to position the red emission filter 139 infront of the CCD array 128 as shown in FIG. 29C. The red emission filter139 allows light having a wavelength of about 621 mm and greater to passto the CCD array 128.

The CPU will then determine in step 1290 whether it is necessary toperform an indexing of the carrier tube 114 as described above. Since noreading has yet been taken with the red emission filter 139 positionedin front of the CCD array 128, the CPU 110 will determine that noindexing is to be performed, and return to step 1250 where it willcontrol the flash tube 126 and CCD array 128 to take a reading with thered emission filter 139 positioned in front of the CCD array 128. TheCPU will then proceed to step 1260 and, if desired, repeat step 1250,until it determines in step 1260 that all reading has been performedwith that particular filter. The CPU proceeds to step 1270 to determineif all desired readings have been taken. Since it determines that alldesired readings have not been taken, the CPU proceeds to step 1280where it controls the filter motor 137 to position the green emissionfilter 138 back in front of the CCD array 128 as shown in FIG. 29B.

The CPU then determines in step 1290 that indexing should be performed,and proceeds to step 1300 to control the rotor motor 108 to cause theindexing mechanism 113 to index or rotate the carrier tube 114 in adirection indicated by arrow INDEX as shown in FIG. 30. As stated above,this indexing process is described in more detail in the aforementionedcopending patent application of Michael R. Walters et al. entitled"Inertial Tube Indexer" Ser. No. 09/032931.

Once this indexing process has occurred, the CPU returns to step 1250where it will take a reading of the sample with the carrier tube 114(and hence the sample tube 478) being in this newly indexed orientation.The CPU 110 then repeats steps 1250-1300 as necessary to take thedesired amount of readings with the green emission filter 138 and redemission filter 139 being positioned as shown in FIGS. 29B and 29C ateach of the index orientation of the carrier tube 114.

In this example, and in the example described in the aforementionedcopending U.S. patent application of Michael R. Walters entitled"Inertial Tube Indexer" Ser. No. 09/032,931, the carrier tube 114 isindexed 8 times. In other words, the carrier tube 114 is rotated by 45°for each indexing step, and green emission readings and red emissionreadings are taken for each of the 8 indexing positions about thecircumference of the carrier tube 114. This entire process for takingred and green emission readings at each of the 8 indexed positions takesapproximately 35-40 seconds.

After the red and green emission readings are all taken, the CPU 110will determine in step 1270 that all readings have been taken. The CPU110 will then proceed to step 1310 where it will calculate the cellcounts for the platelets, granulocytes, lymphocytes and monocytes in thebuffy coat region. The CPU 110 will also be able to calculate the redcell count based on the detected position of the float 282 and the plug286. The results can be then displayed on the graphics display 146and/or printed out by the thermal printer 148.

Although a specific order of reading and indexing is described above,the CPU 110 can be programmed to perform the readings and indexings inany suitable order.

Although only a few exemplary embodiments of this invention have beendescribed in detail above, those skilled in the art will readilyappreciate that many modifications are possible in the exemplaryembodiments without materially departing from the novel teachings andadvantages of this invention. Accordingly, all such modifications areintended to be included within the scope of this invention as defined inthe following claims.

What is claimed is:
 1. A method for centrifuging and reading a fluidsample, and for using an optical reader assembly with a centrifugedevice which operates to centrifuge the fluid sample, comprising thesteps of:rotating a container which contains the fluid sample, toseparate the fluid sample into a plurality of component layers in thecontainer; positioning, relative to the container with the fluid sample,an optical reader that is adaptable to receive light emitted from thefluid sample; controlling the optical reader to cause the optical readerto receive the emitted light from different layers of the fluid samplein the container while the container with the fluid sample is beingrotated by the centrifuge device; and detecting the component layers inthe fluid sample in the container while the container is rotating.
 2. Amethod as claimed in claim 1, further comprising the step ofsubstantially prohibiting a portion of the emitted light having aparticular wavelength from being received by the optical reader.
 3. Amethod as claimed in claim 2, wherein the substantially prohibiting stepcomprises the step of:selectively substantially prohibiting portions ofthe emitted light having respective wavelengths from being received bythe optical reader.
 4. A method as claimed in claim 1, furthercomprising the step of:emitting excitation light toward the fluid sampleto cause the sample to emit the emitted light in response thereto.
 5. Amethod as claimed in claim 1, further comprising the steps of:emittingtransmission light toward the fluid sample; and causing the opticalreader to receive a portion of the transmission light which passesthrough the fluid sample.
 6. A method as claimed in claim 1, wherein thecontrolling step comprises the step of:moving the optical readerincrementally, such that the optical reader receives the emitted lightfrom different portions of the fluid sample as the optical reader isbeing moved incrementally.
 7. A method of centrifuging and reading afluid sample, comprising the steps of:rotating a container whichcontains a fluid sample, to separate the fluid sample into a pluralityof component layers in the container; and detecting the component layersin the container while the container is rotating.
 8. A method as claimedin claim 1, further comprising the steps of:controlling a speed at whichthe container is rotated, such that the speed at which the container isrotated to separate the fluid sample into the component layers isdifferent from the speed at which the container is rotated when thecomponent layers are being detected.
 9. A method as claimed in claim 1,wherein:the rotating step comprises the steps of:releasably mechanicallycoupling the container to a rotor; and rotating the rotor; and themethod further comprises the step of:detecting a rotational orientationof the rotor.
 10. A method as claimed in claim 9, wherein:the rotorcomprises an optical component; and the rotor orientation detecting stepcomprises the step of detecting the optical component of the rotor todetect the rotational orientation of the rotor.
 11. A method as claimedin claim 9, wherein:the component layers detecting step detects thecomponent layers when the rotor orientation detecting step detects thatthe rotor is at a layer detecting orientation.
 12. A method as claimedin claim 9, further comprising the step of:detecting whether thecontainer is releasably mechanically coupled to the rotor.
 13. A methodas claimed in claim 12, wherein:the container detecting step comprisesthe steps of:emitting transmission light toward the rotor; detecting fora portion of the transmission light; and determining whether thecontainer is releasably mechanically coupled to the rotor based ondetection or non-detection of the portion of the transmission light. 14.A method as claimed in claim 13, wherein:the rotor comprises an openingwhich is adaptable to allow the portion of the transmission light topass therethrough; and the container detecting step comprises the stepof substantially preventing the portion of the transmission light frompropagating through the opening when the container is at a propercontainer loading position in the rotor.
 15. A method as claimed inclaim 1, wherein:the component layers detecting step comprises the stepof receiving light emitted from the fluid sample to detect the componentlayers.
 16. A method as claimed in claim 15, wherein:the emitted lightreceiving step comprises the step of receiving the emitted light fromdifferent portions of the fluid sample at different times.
 17. A methodas claimed in claim 15, further comprising the step of:substantiallyprohibiting a portion of the emitted light having a particularwavelength from being received.
 18. A method as claimed in claim 15,further comprising the step of:selectively substantially prohibiting aportion of the emitted light having a respective wavelength from beingreceived.
 19. A method as claimed in claim 15, further comprising thestep of:emitting excitation light toward the fluid sample to cause thesample to emit the emitted light in response thereto.
 20. A method asclaimed in claim 15, further comprising the steps of:emittingtransmission light toward the fluid sample; and receiving a portion ofthe transmission light which passes through the fluid sample.